ESA’s Rosetta is now taking images from just 61 km from comet 67P/Churyumov-Gerasimenko. That is close enough so Rosetta is imaging the comet in about quarters.
The above four-image mosaic is featured at the Rosetta blog was taken on 31 August 2014. It’s really not quite a mosaic yet If you look at the four-panels you will see some overlap. The images were made from 20 minute exposures and there is also some rotation from the mutual movement of Rosetta and comet.
We, the public are invited to create a mosaic from them. Rosetta Blog has the four individual frames on the page for downloading which I have done. Just scroll down the page linked above to get the individual shots.
I have everything loaded into a imaging program and working on my mosiac. The rotation is creating quite a challange!
Give it a try. I’ll post my effort if I can get anywhere with it.